A panoramic view of the Apollo 17 landing site. Harrison Schmitt prepares to take a soil sample, in this photograph taken by Eugene Cernan, in December of 1972. The last men to walk on the Moon returned home only a few days later. It has been more than thirty years since the last Moon mission; how long will it be before men walk on the Moon again? (Apollo 17 Crew, USGS, NASA, apod020128)